Answer:
18th customer
Explanation:
The computation is shown below
Here we have to write the multiples of 6 and multiples of 9 that are presented below:
Multiples of 6: 6, 12, 18, 24, 30, 36, 42, 48
Multiples of 9: 9, 18, 27, 36, 45, 54, 63, 72
So based on the above multiples of 6 and 9, 18th customer would first to receive a free rose and a lily